Method for operating a system having visible light sources and sensors for bidirectional communication and system having visible light sources and sensors for biderectional communication

ABSTRACT

A system includes vehicles, a central control unit, and a stationary transceiver module connected to the central control unit via a bidirectional communications channel. Each has a transceiver module for bidirectional communication with the stationary transceiver module and/or a vehicle. The transceiver module has a controllable light source and a light sensor. The central control unit transmits driving orders to the vehicles via the stationary transceiver module. A first vehicle that is located within the spatial transmission area of the stationary transceiver module forwards a driving order to a second vehicle that is located outside the spatial transmission area of the stationary transceiver module, and the second vehicle transmits data via the first vehicle and the stationary transceiver module to the central control unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/781,750, which is the national stage of PCT/EP2016/025157,having an international filing date of Nov. 30, 2016, and claimspriority to Application No. 102015015770.1, filed in the FederalRepublic of Germany on Dec. 8, 2015, each of which is expresslyincorporated herein in its entirety by reference thereto.

FIELD OF THE INVENTION

The present invention relates to a method for operating a system, and toa system.

BACKGROUND INFORMATION

A system for a plant and a method for operating such a system isdescribed in German Published Patent Application No. 10 2013 001 358.

German Published Patent Application No. 10 2009 043 060 shows a systemof mobile robots having a base station.

SUMMARY

Example embodiments of the present invention provide a method foroperating a system as well as a system, and improving the safety in theprocess.

According to an example embodiment of the present invention, in a methodfor operating, especially for controlling, a system that includesvehicles, a central control unit, and at least one transceiver module,which is stationary, is connected to the central control unit by abidirectional communications channel, and has a spatial transmissionarea, in particular a transmission cone, each vehicle has a transceivermodule, each particularly having a spatial transmission area for thebidirectional communication with the stationary transceiver moduleand/or a vehicle, the respective transceiver module has at least onecontrollable light source and a light sensor, in particular a lightsource of visible light and a light sensor for visible light, thecentral control unit transmits driving orders to the vehicles with theaid of the stationary transceiver module, a first vehicle located in thespatial transmission area of the stationary transceiver module forwardsa driving order to a second vehicle that is located outside the spatialtransmission area of the stationary transceiver module, the secondvehicle transmitting data, in particular status information, to thecentral control unit with the aid of the first vehicle and thestationary transceiver module.

This has the advantage that light sources provided for illuminationpurposes are able to be used for the data transmission. With the aid ofthe vehicles, the number of stationary light sources is able to bereduced at a high transmission range.

Obstacles for the transmitted light of the stationary transceiver moduleare able to be circumvented by the vehicles.

Visible light can easily be generated by simple, cost-effective lightsources, in particular LEDs, and easily be detected using simple,cost-effective sensors, in particular photodiodes or phototransistors.

Each vehicle may have a position-determination device, in particularincluding an odometric sensor and/or a GPS sensor, and transmits itsposition data, determined by the position-determination device, with theaid of the stationary transceiver module and/or the first vehicle to acentral control unit. This has the advantage that the position of eachvehicle is able to be determined independently of the central controlunit. In an advantageous manner, this makes it possible to determine theposition of a vehicle outside the spatial transmission areas of thestationary transceiver module and the transceiver modules of the othervehicles. This increases the range of the system.

Each vehicle may determine the position data of vehicles that arelocated in its spatial transmission area relative to itself andtransmits these determined relative position data with the aid of thestationary transceiver module to the central control unit. This offersthe advantage that the collision risk among the vehicles is able to bereduced. When preparing the driving orders, the central control unittakes the relative positions of the vehicles into account and calculatesthe driving routes such that the vehicles will not collide. Thisimproves the safety.

The central control unit may use the position data of each vehicle, therelative position data of the vehicles, and the position of thestationary transceiver module in order to determine position correctionsand transmits them to the vehicles. This is considered advantageousinasmuch as it improves the precision of the respective position,determined with the aid of the position-determination device, becausethe position corrections may be utilized for determining referencepositions.

The driving order for a respective vehicle may include

-   -   a destination and/or    -   a starting point and/or    -   a driving route and/or    -   a velocity and/or    -   a release for a route section of the driving route and/or    -   a maximum driving time.

This has the advantage that the driving order for a respective vehicleis precisely specified by the central control unit. The setpointposition of the vehicle may be predefined for each instant. This makesit possible to easily locate the vehicle in the event of a fault.

A vehicle that is located outside the spatial transmission area of allother vehicles and of the stationary transceiver module at thedestination point of its driving order automatically may return to thestarting point of its driving order. This has the advantage of enlargingthe range of the system without increasing the number of vehicles or thenumber of the stationary transceiver modules. It is thereby possiblethat a vehicle leaves a building that houses the system andautomatically returns after carrying out its driving order.

The vehicle requires no additional driving order for its return. Thevehicle may drive in the reverse direction of its previous drivingorder.

The actual position of the vehicle, instantaneously determined with theaid of the position-determination device, may be controlled to asetpoint position that is current according to the driving route. Thishas the advantage that the vehicle requires no additional driving orderfor its return. The vehicle may drive in the opposite direction of itsprevious driving order.

As soon as a vehicle remains outside the spatial transmission areas ofall other vehicles and of the stationary transceiver module for longerthan the predefined maximum driving time of its driving order, thecentral control unit may transmit a driving order, which includes adriving route that is identical to the driving order of the vehicle, toa further vehicle. After establishing a communications link to thevehicle, the further vehicle receives the status information of thevehicle, stores it, drives back to the starting point of the drivingorder of the further vehicle and transmits the status information of thevehicle to the central control unit. This has the advantage thatvehicles are able to be located in the event of a fault. The statusinformation may be analyzed by the central control unit, and the vehiclemay be recoverable by other vehicles and/or may be assigned a newdriving order. The safety is therefore improved.

The second vehicle may receive a driving order from the first vehicleand forwards this driving order to another vehicle. This offers theadvantage that driving orders are able to be forwarded via multiplevehicles. The driving orders of all vehicles may be stored in eachvehicle so that each vehicle is locatable by each other vehicle on thebasis of its driving order.

The second vehicle may store a driving order and may forward it with atime delay, which has the advantage of improving the range of thesystem.

The second vehicle may receive a first and a second driving order, andthe second vehicle may carry out the first driving order and may storethe second driving order. After establishing a communications link tothe further vehicle, the second vehicle transmits the second drivingorder to the further vehicle. This has the advantage that the secondvehicle is able to be dispatched to the further vehicle with the aid ofthe first driving order so that the second driving order is able to beforwarded to the further vehicle.

According to an example embodiment of the present invention, in thesystem, in particular for executing a method as described herein, thesystem includes vehicles and at least one transceiver module, which isdisposed in a stationary manner and has a spatial transmission area, inparticular a transmission cone, each vehicle has a respective firsttransceiver module, a respective second transceiver module, and arespective position-determination device, in particular including anodometric sensor and/or a GPS sensor, and/or a respective distancesensor, in particular a radar sensor and/or an ultrasonic sensor. Therespective transceiver module has at least one controllable light sourceand a light sensor, in particular a light source of visible light and alight sensor for visible light. Each vehicle is arranged for thebidirectional communication with the stationary transceiver module usingthe respective first transceiver module, and using the respective secondtransceiver module, is arranged for the bidirectional communication withthe respective other vehicles with the aid of their respective secondreceiver modules. This has the advantage that light sources that areprovided for an illumination may be used for the transmission of data.The number of stationary light sources is able to be reduced by thevehicles at a high transmission range.

Obstacles for the transmitted light of the stationary transceiver moduleare able to be circumvented by the vehicles.

Visible light can be generated using simple, cost-effective lightsources, in particular LEDs, and is able to be detected using simple,cost-effective sensors, in particular photodiodes or phototransistors.

The system may have a central control unit for the control of thevehicles; the central control unit may be connected to the stationarytransceiver module with the aid of at least one bidirectionalcommunications channel, the central control unit being designed totransmit driving orders to a respective vehicle using the stationarytransceiver module. This has the advantage that it is possible toactuate all vehicles of the system using a single central control unit.The collision risk is therefore able to be reduced since all vehiclesare centrally controllable and all driving orders are able to becoordinated with one another.

Each vehicle may have a memory in which position data of the stationarytransceiver module and/or respective identifying information and/orposition data of the respective vehicle are stored. This offers theadvantage that position data are able to be transferred with the aid ofthe vehicle, especially able to be transferred with a time delay. Theseposition data may be used as reference points for determining theposition of the vehicles with the aid of position-determination device,which improves the accuracy of the position determination.

The memory of the respective vehicle may be arranged to store drivingorders for a further vehicle. This is considered advantageous sincedriving orders are able to be transferred with a time delay utilizingthe vehicles.

The stationary transceiver module may be disposed above the vehicles.This is considered advantageous since the data transmission may becarried out in a vertical direction where fewer obstacles for light arelocated.

The respective first transceiver module of a respective vehicle may bedisposed on the particular vehicle in alignment with the stationarytransceiver module. This offers the advantage that the data transmissionmay be carried out in a vertical direction where fewer obstacles forlight are located.

The system may have a plurality of stationary transceiver modules, whichare set apart from one another, the spatial transmission areas of thestationary transceiver modules, in particular, being set apart from oneanother, and each stationary transceiver module may be connected to thecentral control unit at least via one bidirectional communicationschannel. This has the advantage that the transmission of the data and/orthe driving orders is able to be accelerated in that the driving routesof the vehicles to the stationary transceiver modules are able to beshortened.

The stationary transceiver modules may act as reference points for theposition determination of the vehicles with the aid of theposition-determination device, which therefore improves the accuracy ofthe position determination.

Each vehicle may have at least one third transceiver module, the thirdtransceiver module being arranged for the communication with therespective second and/or third transceiver module(s) of the othervehicles. This offers the advantage that it allows for an enlargement ofthe spatial transmission area of the respective vehicle.

The spatial transmission area of the respective second transceivermodule and the spatial transmission area of the respective thirdtransceiver module may jointly cover a larger spatial area than thesecond or the third spatial transmission areas. This offers theadvantage of allowing for an enlargement of the spatial transmissionarea of the vehicle.

The respective second transceiver module may be aligned in the drivingdirection of the respective vehicle, and the respective thirdtransceiver module may be aligned counter to the driving direction ofthe respective vehicle. This has the advantage that the spatialtransmission areas of the transceiver modules of a respective vehicleminimally overlap with one another so that the entire spatialtransmission area of the respective vehicle is able to be maximized.

Further features and aspects of example embodiments of the presentinvention are described in greater detail below with reference to theappended FIGURE.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a system of vehicles according to an example embodiment ofthe present invention in a side view.

DETAILED DESCRIPTION

The system includes at least one stationary transceiver 20 module andvehicles that have at least two transceiver modules in each case.

The system may be disposed inside a building, in particular a warehouseor a production hall. The vehicles (2, 3, 4) drive on a driving surface15 on the floor of the building. The stationary transceiver module issituated above the vehicles (2, 3, 4), e.g., on ceiling 16 of thebuilding.

In a further exemplary embodiment, the system is used outdoors. Thestationary transceiver module is mounted on a post, especially a lamppole, and aligned with respect to the ground, in particular drivingsurface 15.

In a further exemplary embodiment, the vehicles (2, 3, 4) drive bothoutdoors and inside a building, and at least one stationary transceivermodule is disposed in the hall, and/or at least one stationarytransceiver module is situated outside.

Each transceiver module has a controllable light source (1, 5, 6, 7, 8,9, 10, 11, 12, 13) of visible light and a light sensor for visiblelight. Each light source (1, 5, 6, 7, 8, 9, 10, 11, 12, 13) has aspatially restricted spatial transmission area, in particular atransmission cone 14.

As a result, the building is able to be illuminated by the stationarytransceiver unit.

The stationary transceiver module 20 is connected to a central controlunit 22 with the aid of a bidirectional communications channel. Thecentral control unit 22 controls the stationary transceiver module 20,thereby actuating light source 1 of the stationary transceiver unit toemit a communications signal in the form of intensity-modulated light.

A light sensor of a transceiver module of a vehicle (2, 3, 4) detectsthe intensity-modulated light, and a signal electronics system of thetransceiver module evaluates the received communications signal.

The central control unit uses the stationary transceiver module totransmit driving orders to the vehicles (2, 3, 4).

A driving order for a respective vehicle (2, 3, 4) includes

-   -   a destination and/or    -   a starting point and/or    -   a driving route and/or    -   a velocity and/or    -   a release for a route section of the driving route and/or    -   a maximum driving time.

Each vehicle (2, 3, 4) has a first transceiver module for thebidirectional communication with the stationary transceiver module. Therespective first transceiver module may be disposed on the upper side ofeach vehicle (2, 3, 4).

Using the first transceiver module, the respective vehicle (2, 3, 4)transmits data, especially status data, to the stationary transceivermodule, which forwards the data to the central control unit.

Each vehicle (2, 3, 4) has at least one second transceiver module forthe bidirectional communication with another vehicle (2, 3, 4). Therespective second transceiver module is situated such that it istransversely aligned with respect to a normal plane of driving surface15. The respective second transceiver module may be disposed such thatit is aligned in the driving direction of the respective vehicle (2, 3,4).

As schematically illustrated in FIG. 1, each vehicle (2, 3, 4) may havea third transceiver module (24, 26, 28), which is disposed such that theregion covered by the spatial transmission area of the secondtransceiver module and by the spatial transmission area of the thirdtransceiver module (24, 26, 28) is greater than the spatial transmissionarea of the second transceiver module and greater than the spatialtransmission area of the third transceiver module (24, 26, 28). Therespective second transceiver module and the respective thirdtransceiver (24, 26, 28) module may be situated opposite from eachother. The respective third transceiver (24, 26, 28) module may besituated counter to the driving direction of the respective vehicle (2,3, 4).

Using the second and/or the third transceiver module(s), the vehicles(2, 3, 4) exchange status data such as position data and/or errorreports and/or driving orders.

An ad-hoc network is therefore created that considerably improves therange of the system.

Each vehicle (2, 3, 4) has at least one distance sensor, in particular aradar sensor and/or an ultrasonic sensor, and/or an anti-collisionsystem.

In addition, each vehicle (2, 3, 4) has a position-determination device,in particular an odometric sensor and/or a GPS sensor.

Using the odometric sensor, the position of the respective vehicle (2,3, 4) relative to a starting point and/or an initialization point isable to be determined independently of reference points with the aid ofan angle sensor on a drive of the respective vehicle (2, 3, 4).

The GPS sensor may be used to determine the absolute position of therespective vehicle (2, 3, 4). The system may have a reference pointwhose precise position data are known so that a comparison of theposition data of the respective vehicle (2, 3, 4) with the position dataof the reference point—referred to as a differential GPS—makes itpossible to determine the absolute position of the respective vehicle(2, 3, 4) with high precision even inside a building.

Each vehicle (2, 3, 4) has a memory unit. The memory unit is arranged tostore driving orders and/or status data and/or identifying information.

A first vehicle 3 that is located in the spatial transmission area ofthe stationary transceiver module receives a driving order from thecontrol unit and forwards this driving order to a second vehicle (2, 4)which is located outside the spatial transmission area of the stationarytransceiver module.

First vehicle 3 located in the spatial transmission area of thestationary transceiver module receives status data of the second vehicle(2, 4), which is located in the spatial transmission area of the secondand/or third transceiver module of first vehicle 3. First vehicle 3forwards the status data of the second vehicle (2, 4) to the centralcontrol unit with the aid of its first transceiver module and thestationary transceiver module.

Each vehicle (2, 3, 4) ascertains the relative position data of vehicles(2, 3, 4) that are located in the respective spatial transmission areaof its second and/or third transceiver module(s) relative to its ownposition and forwards these position data with the aid of the stationarytransceiver module and/or a transceiver module of a further vehicle tothe central control unit.

Using the known absolute position of the stationary transceiver module,the relative position data of the vehicles (2, 3, 4), and the positiondata of the vehicles (2, 3, 4) determined with the aid of the respectiveposition-determination device, the central control unit determinesposition corrections for the respective vehicles (2, 3, 4) and transmitsthese position corrections to the vehicles (2, 3, 4). The individualvehicle uses these position corrections to correct the position datadetermined with the aid of the position-determination device.

A vehicle that is located outside the spatial transmission areas of allother vehicles and the stationary transceiver module after carrying outits driving order, i.e. is located at the destination, automaticallyreturns to the starting point of its driving order. To do so, thevehicle determines its position with the aid of theposition-determination device and controls this position to a setpointposition according to the driving order. The vehicle may drive the sametravel route that was specified in its previous driving order, doing soin the reverse direction.

As an alternative, the vehicle stops as soon as it has established acommunications link to another vehicle and/or to the stationarytransceiver module and then waits for a new driving order.

As soon as a vehicle is located outside the spatial transmission areasof all other vehicles and the stationary transceiver module for longerthan the predefined maximum driving time of its driving order, thecentral control unit sends a driving order, which includes a drivingroute that is identical to the driving order of the vehicle, to afurther vehicle. The further vehicle follows this route and stops afterestablishing a communications link to the vehicle. The further vehiclereceives and stores the status information of the vehicle and drivesback to the starting point of the driving order of the further vehicle,where it transmits the status information of the vehicle to the centralcontrol unit.

A vehicle may receive a first driving order and a second driving orderfor a further vehicle from the stationary transceiver module, or from afirst vehicle 3 that is located in the spatial transmission area of thestationary spatial transmission area of the stationary transceivermodule. The vehicle executes the first driving order and stores thesecond driving order. As soon as the vehicle has established acommunications link to the further vehicle, it forwards the seconddriving order to the further vehicle.

The system may have more than one stationary transceiver module, and allstationary transceiver modules are connected to a single central controlunit with the aid of a communications channel, in particular abidirectional communications channel, in each case.

The respective spatial transmission areas of the stationary transceivermodules are set apart from one another.

Each vehicle (2, 3, 4) permanently searches for other vehicles (2, 3, 4)or for stationary transceiver modules in the spatial transmission areasof its transceiver modules in order to establish a communications link.As soon as the respective vehicle (2, 3, 4) has established acommunications link, it transmits its status data and receives thestatus data and/or driving orders of the other vehicles (2, 3, 4) or thestationary transceiver modules.

LIST OF REFERENCE NUMERALS

-   1 light source-   2 vehicle-   3 vehicle-   4 vehicle-   5 light source-   6 light source-   7 light source-   8 light source-   9 light source-   10 light source-   11 light source-   12 light source-   13 light source-   14 transmission cone-   15 driving surface-   16 ceiling-   20 stationary transceiver module-   22 central control unit-   24 third transceiver module-   26 third transceiver module-   28 third transceiver module

What is claimed is:
 1. A system, comprising: a plurality of vehicles;wherein each vehicle includes a first transceiver module, a secondtransceiver module, and a position-determination device and/or adistance sensor, each transceiver including a controllable light sourceand a light sensor; and wherein each vehicle is adapted tobidirectionally communicate with a stationary transceiver module usingthe first transceiver module and is adapted to bidirectionallycommunicate with other vehicles using the second transceiver module;wherein the stationary transceiver module includes a controllable lightsource of visible light and the light sensor of at least each vehicleincludes a light sensor for visible light.
 2. The system according toclaim 1, wherein the stationary transceiver module includes a spatialtransmission area and/or a transmission cone.
 3. The system according toclaim 1, wherein the position-determination device includes an odometricsensor.
 4. The system according to claim 1, wherein theposition-determination device includes a GPS sensor.
 5. The systemaccording to claim 1, wherein the distance sensor includes a radarsensor.
 6. The system according to claim 1, wherein the distance sensorincludes an ultrasonic sensor.
 7. The system according to claim 1,wherein the controllable light source of each vehicle includes acontrollable light source of visible light.
 8. The system according toclaim 1, wherein a light sensor of the stationary transceiver moduleincludes a light sensor for visible light.
 9. The system according toclaim 1, further comprising a central control unit adapted to controlthe vehicles, the central control unit connected to the stationarytransceiver module by at least one bidirectional communications channel,the central control unit adapted to transmit driving orders to arespective vehicle via the stationary transceiver module.
 10. The systemaccording to claim 1, wherein each vehicle includes a memory adapted tostore position data of the stationary transceiver module, identifyinginformation of other vehicles, and/or position data of other vehicles.11. The system according to claim 10, the memory unit is adapted tostore driving orders of a further vehicle.
 12. The system according toclaim 1, wherein the stationary transceiver module is disposed above thevehicles.
 13. The system according to claim 1, wherein the firsttransceiver module is arranged on the vehicle in alignment with thestationary transceiver module.
 14. The system according to claim 1,wherein the system includes the stationary transceiver module.
 15. Thesystem according to claim 9, wherein the system includes a plurality ofstationary transceiver modules set apart from one another, spatialtransmission areas of the stationary transceiver modules being set apartfrom one another, each stationary transceiver module being connected tothe central control unit via at least one respective bidirectionalcommunications channel.
 16. The system according to claim 1, whereineach vehicle includes a third transceiver module adapted to communicatewith the second and/or third transceiver module of other vehicles, aspatial transmission area of the second transceiver module and a spatialtransmission area of the third transceiver module jointly covering alarger spatial area than the spatial transmission area of the second orthe third transceiver module, the second transceiver module beingaligned in a driving direction of the vehicle, and the third transceivermodule being aligned counter to the driving direction of the vehicle.17. The system according to claim 1, wherein the vehicles are adapted toreceive driving orders transmitted by a central control unit via thestationary transceiver module; wherein a first one of the vehicles,located in a spatial transmission area of the stationary transceivermodule, is adapted to forward a driving order to a second one of thevehicles located outside the spatial transmission area of the stationarytransceiver module; and wherein the second one of the vehicles isadapted to transmit data and/or status information to the centralcontrol unit via the first vehicle and the stationary transceivermodule.
 18. The system according to claim 1, wherein each vehicleincludes a position-determination device, each vehicle adapted todetermine position data of vehicles that are located in its spatialtransmission area relative to itself, and to transmit the determinedrelative position data via the stationary transceiver module to acentral control unit adapted to determine position corrections based onthe position data of each vehicle, relative position data of thevehicles, and a position of the stationary transceiver module andtransmitting the position corrections to the vehicles.
 19. The systemaccording to claim 9, wherein the driving order includes a destination,a starting point, a driving route, a velocity, a release for a routesection of the driving route, and/or a maximum driving time.
 20. Thesystem according to claim 9, wherein each vehicle is adapted toautomatically return from a destination point of the driving order,outside the spatial transmission areas of all other vehicles and thestationary transceiver module, to a starting point of the driving order.